Ten users from the University of Wisconsin-Madison are applying for a Biomedical Research Support Shared Instrumentation Grant to purchase equipment to expand a Protein Microsequencing Facility of the newly formed University of Wisconsin Biotechnology Center. We propose to add to our facility a) a gas-phase protein microsequencer to carry out sequential Edman degradation of proteins at a subnanomole scale, b) an HPLC for analyzing on line the resulting PTH-amino acid derivatives, c) an HPLC for purifying proteins and peptides prior to sequencing, d) an amino acid analyzer, and e) necessary accessory equipment. The ability to sequence subnanomole amounts of proteins and peptides will be invaluable in studies of difficult-to-purify proteins and in obtaining peptide sequence data to confirm DNA sequencing results. A very important and exciting use is to clone genes for non-abundant proteins. Amino acid sequence information will be obtained and used to design DNA oligonucleotides that can be used as a hybridization probe to identify the gene of interest in gene libraries. Projects proposed here include the study of: 1) enzymes and proteins central to regulating the expression of genetic information (Burgess, Dahlberg, Reznikoff); 2) structure and function of proteins involved in calcium channels (Kung); 3) enzymes known to be deficient in human disease (Pitot); 4) structure and synthesis of small RNA viruses (Rueckert); 5) structure of proteins involved in the interaction of acyl CoAs with ADP/ATP carrier (Shrago); 6) enzymology of vitamin K-dependent carboxylase and structure of modified prothrombin (Suttie); 7) control of antibiotic resistance (Weisblum); and 8) regulation, extracellular export and structure of cytolytic proteins (Welch). This facility will give a large number of faculty who are conducting NIH-supported research increased access to a very powerful new technology. This technology will contribute significantly to the success of much of this research and is essential for maintaining the strength and continued progress of many research programs at this University.